Advanced Driver Assistance Systems (ADAS) increase vehicle safety and road safety, and pave the way for realizing the autonomous vehicles. An ADAS avoids collisions and accidents by using technologies that alert drivers of potential dangers, or by implementing safeguards and taking over control of the vehicles. To function properly and provide good user experience, an ADAS needs to accurately understand a vehicle's real-time operation status, such as whether or not the vehicle is moving. For example, many features of an ADAS, including collision warning/avoidance and lane departure warning, only work well after the vehicle enters a normal driving mode. When the vehicle stops or moves at a low speed (e.g., when the driver attempts to park the vehicle in a crowded space), these ADAS features may need to be turned off. Therefore, it is desirable to determine the vehicle's motion information in real time and automatically turn on/off the ADAS based on the motion information.
Conventionally, an ADAS may include a Global Positioning System (GPS) module for connecting to an external GPS receiver. The GPS receiver feeds the vehicle's motion information, such as the vehicle speed, to the ADAS. However, the GPS receiver may have poor reception in a covered space (e.g., a tunnel) or in a city street surrounded by tall buildings. Also, the GPS information may not be accurate when the vehicle stops or is at a low speed. Moreover, for a portable GPS receiver, the driver may have to frequently connect/disconnect the GPS receiver to/from the ADAS. For example, to prevent theft, the driver needs to disconnect the GPS receiver from the ADAS after each driving session, and reconnect the GPS receiver when starting the next session. This is cumbersome for the driver.
The disclosed methods and systems address one or more of the problems listed above.